Abstract




 
   

Vol. 5, No. 1&2 (May 1992) 39-48   

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  STRUCTURAL AND MECHANICAL CHARACTERIZATION OF AUSTEMPERED CU - SN DUCTILE IRON ALLOYS
 
 
M.A. Golozar and A. Najafi-Zadeh

 Department of Materials Engineering
Isfehan University of Technology
Isfehan, Iran

 
 
 
 

Abstract    The effect of heat treatment and alloying elements of copper and tin on the microstructure and mechanical properties of austempered ductile cast iron alloys is investigated. The austenitizing temperature of 890°C, the isothermal transformation (austempering) temperatures of 285, 335 and 375°C, and austempering times of 15, 30, 75 and 150 minutes are studied. The alloying elements of copper and tin are varied within the range of 0 -1.5% and 0 - 0.4%, respectively. The results obtained indicate that the microstructure and mechanical properties of austempered ductile Cu-Sn iron alloys are significantly influenced by the isothermal transformation time and temperature. The alloying elements of copper and tin have a pronounced effect on the matrix microstructure of as-cast and annealed ductile irons. These elements show no effect on the morphology of bainite in the austempered condition. However, the volume fraction of retained austenite in the austempered ductile iron alloys increase due to the addition of these elements. The mechanical properties of austempered ductile iron alloys are also significantly influenced by alloying elements. At austempering temperatures of 375 and 335°C, the 1% Cu - 0.4%Sn ductile iron alloy austempered for 75 minutes shows the optimum combination of mechanical properties. Conversely, at austempering temperature of 285°C, the 1% Cu - 0.2% Sn ducitile iron alloys austempered for 30 minutes represent the optimum combination of mechanical properties.

 
 

References   

1. Grigy, C. and La Gal” Founderie Foundeur d 'Aujourd' hui, No. 8, (Oct. 1981), 21-24.

2. Dodd, J.”Modern casting, (May. 1978), 60-66.

3. Sharma, V. K. , J. of Heat Treating, Vol. 3, (1984).

4. Hughes, J. C. H. “ Br.Foundaryman, Vol. 24, (1981), 229-245.

5. Luijendijk, T. and Nieswaage, H., 50th Int. Foundary Congress, Cario, No. 9, (1983).

6. Speidel, M. O.and Uggowitzer, P., 51 st,Int. Foundary Congress, Lisboa, No. 28, (1984).

7. Speidel, M. O.,“ Z.Werkstofftechnik, Vol. 12, (1981), 387-402.

8. Rossi, F. S.,“ Metal Progress, Vol. 119, No. 5, (1981), 25-31.

9. KovacsSr, B. K., “, J. of Heat Treating, Vol. 5, No. 1, (1987),65-79.

10. Tiziani, A., “55th Int. Foundary Congress, Italy, (Sept. 1988), 423-432.

11. Bhadeshia, H. K. and Edmonds, D. V., Metall. Trans., Vol. 10, (1979), 1985-1992.

12. Metals,S. J. and Hehemann, R. F., Trans. AIME, Vol. 221, (1961), 179-185.

13. Sandvik, B. P. J., Metal. Trans., Vol. 13, (1982) .

14. Johansson, M., AFS Trans., Vol. 85, (1977), 117-122.

15. Dorazil, E., Giesserei praxis, Vol. 18, (1979), 355-366.

16. Janowak, J. F. and Gundlach, R. B., AFS Trns., Vol. 26, (1983), 377-388.

17. Janowak, J. F. and Morton, P. A., AFS Trans, Vol. 27, (1984), 489-498.

18. Gundlack, R. B. and Janowak, J. F., 1st Int. Conf. on ADI, Chicago, USA, 2-4, (April. 1984), 1-12.

19. Dorazit, E., AFS Int. Cast. Met.J., Vol. 7, No. 2, (1982), 52-62.

20. Jaferian, M., Tavakoli, F. and Davami, P., First IFS congress Tehran,Iran, (1988), 34-45.

21. Najafi-zadeh, A. and Golozar, M. A., Second IFS Congress, Tehran, Iran, (1989), 76-98.

22. Najafi-zadeh, A. and Golozar, M. A., Esteghlal, Journal of Eng., IUT, Iran, No. 8, (June. 1990), 32-60.

23. Emami, M. and Hedjazi, Dj. , Third IFS Congress, Tehran, Iran, No. 9, (1991).

24. Rundman, K. B., J. of Heat Treating, Vol. 5, No. 2, (1988), 79-95.

25. Stenfords, S. E. , Technical report, Department of Metallurgy, Royal Institute of Technology, S-100 44 Stockholm, Sweden.

26. Shiokawa, T., 59th Japan Ductile Cast Iron Assoc.,Licensee conf., (1978), 235-246.

27. Nieswaag, H. and Nijhof,” Technical report, Laboratorium voor Metalkunde, Dell University of Technology, The Netherland, (1988).

28. Bhadeshia, H. K. and D. V. Edmonds, Metal Science, Vol. 17, (1983), 411-419.

29. Najafi-Zadeh, A. and Golozar, M. A., Austempered Ductile Irons, Final year Research projects, Faculty of Materials Eng., IUT, Iran, (1988-1989).

30. Golozar, M. A. and Najafi-Zadeh, A., “ADI, research reports, Faculty of Materials Eng., IUT, Iran, (1989-1990).





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